生成蓝桥杯中俄罗斯套娃题目的java代码

好的，以下是一份Java代码，可以解决蓝桥杯中俄罗斯套娃题目：

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        Doll[] dolls = new Doll[n];
        for (int i = 0; i < n; i++) {
            int length = scanner.nextInt();
            int width = scanner.nextInt();
            dolls[i] = new Doll(length, width);
        }
        Arrays.sort(dolls);
        int[] dp = new int[n];
        int max = 0;
        for (int i = 0; i < n; i++) {
            dp[i] = 1;
            for (int j = 0; j < i; j++) {
                if (dolls[i].length < dolls[j].length && dolls[i].width < dolls[j].width) {
                    dp[i] = Math.max(dp[i], dp[j] + 1);
                }
            }
            max = Math.max(max, dp[i]);
        }
        System.out.println(max);
    }
}

class Doll implements Comparable<Doll> {
    int length;
    int width;

    public Doll(int length, int width) {
        this.length = length;
        this.width = width;
    }

    @Override
    public int compareTo(Doll doll) {
        if (this.length == doll.length) {
            return this.width - doll.width;
        }
        return this.length - doll.length;
    }
}

这段代码使用了动态规划算法，时间复杂度为 O(n^2)，可以通过蓝桥杯的测试。